Image forming apparatus

Abstract

An image forming apparatus includes an electrostatic latent image bearer; a charger to charge a surface of the electrostatic latent image bearer; a power source to output a charging bias supplied to the charger; an electrostatic latent image writing unit to write an electrostatic latent image on the surface of the electrostatic latent image bearer charged by the charger; a developing unit including a developing member to develop the electrostatic latent image to obtain a toner image; a developing power source to output a developing bias supplied to the developing unit; a processor to adjust the charging bias output from the power source to a predetermined target value; and a storage unit to store an adjustment value algorithm.

What is claimed is: 
     
       1. An image forming apparatus, comprising:
 an electrostatic latent image bearer; 
 a charger to charge a surface of the electrostatic latent image bearer; 
 a power source to output a charging bias supplied to the charger; 
 an electrostatic latent image writing unit to write an electrostatic latent image on the surface of the electrostatic latent image bearer charged by the charger; 
 a developer including a developing member to develop the electrostatic latent image to obtain a toner image; 
 a developing power source to output a developing bias supplied to the developer; 
 a memory to store an adjustment value algorithm to determine an adjustment value, the adjustment value to decrease an amount of a background potential from an optimal background potential due to output error with respect to the charging bias outputted by the power source and output error with respect to the developing bias outputted by the developing power source, the background potential being a potential difference between a surface of the developing member and a background portion of the electrostatic latent image bearer; and 
 a processor to adjust either only the charging bias output from the power source, or only the developing bias output from the developing power source by adding the adjustment value, 
 wherein the output error with respect to the charging bias outputted by the power source is a deviation from a target charge bias, and 
 wherein the output error with respect to the developing bias outputted by the developing power source is a deviation from a target developing bias. 
 
     
     
       2. The image forming apparatus of  claim 1 , wherein the adjustment value consists of a single value. 
     
     
       3. The image forming apparatus of  claim 1 , wherein the power source outputs a DC charging bias. 
     
     
       4. The image forming apparatus of  claim 1 ,
 wherein a plurality of combinations of the electrostatic latent image bearer, the charger, the power source, the developing unit, and the developing power source forms toner images of different colors, 
 wherein the adjustment values for each of the plurality of combinations are stored in the memory, and 
 wherein the processor adjusts either only the charging bias output from the power source or only the developing bias output from the developing power source by adding the adjustment value in each of the plurality of combinations. 
 
     
     
       5. The image forming apparatus of  claim 1 , wherein the developing unit employs developer including toner and carrier particles.